A new Wavelet based Edge detection Technique for Iris Imagery

摘要

In this paper, we present a novel design of a wavelet based edge detection technique. Edge detection is an important task in image processing. Edges in images can be mathematically defined as local singularities. Until recently, the Fourier transforms was the main mathematical tool for analyzing singularities. However, the Fourier transform is global and not well adapted to local singularities. It is hard to find the location and spatial distribution of singularities with Fourier transforms. Wavelet analysis is a local analysis; it is especially suitable for time frequency analysis, which is essential for singularity detection. The fact motivated us to develop a technique using Haar wavelet to find an edge from an image. The proposed technique has been demonstrated for iris imagery and the reported results have been compared with Daubechies D4 wavelet based edge detection technique.